The invention is concerned with apparatus for moving measuring and testing devices or apparatus through a pipeline having limited access thereto.
Specifically, the invention is concerned with the testing and checking of pipelines which have a diameter in the range of 70 to 500 millimeters. The devices are generally used to inspect a pipeline by means of a television-type of camera which is carried, pushed or pulled through the pipeline so that the interior of the pipeline may be viewed, particularly for those interior areas of the pipeline which are not viewable or accessible by other means.
In some instances, drawings indicating the characteristics of the interior of a pipeline are not available so that it becomes difficult to ascertain the interior characteristics. For example, it may be necessary to locate a lead-off from a pipeline and distinguish it from a leak. For various reasons, it has now become necessary to obtain a pictorial view of the interior characteristics of a pipeline.
Additionally, it is important that the characteristics of the flow pattern in a pipeline be checked, particularly in those areas where the flow is not readily known from the outside. In this way, leakage and other types of losses in the fluid flowing in the pipeline can be detected. It is also possible to detect for gas leakage into or out of the pipeline.